docs: def sdk_normalize(filename):
      """
      Normalize a path to strip out the SDK portion, normally so that it
      can be decided whether it is in a system path or not.
      """
      if filename.startswith('/Developer/SDKs/'):
          pathcomp = filename.split('/')
          del pathcomp[1:4]
          filename = '/'.join(pathcomp)
      return filename